Luck is the intersection of opportunity and preparation.
In other words: "Luck." Without clairvoyance ie knowing what to prepare for, when, and to what extent, preparation can be filed under wasted resources, wasted time, etc. Unless of course you get lucky guess right. And were lucky enough to be able to have access to the necessary resources. But you could still end up being successful anyway, if you get lucky.
Opportunity equals luck. I think this is what they call a tautology.